Mechanical drive

ABSTRACT

A mechanical drive is provided for actuating the tuning means in radio equipments for converting a uniform rotary movement into a non-uniform rotary movement with the aid of camplates. The two camplates of almost the same shape and size are arranged paraxially next to each other, the face surfaces thereof almost touch each other, and said camplates are in connection with one another via a tape which, upon actuation of the drive shaft, extends from the circumference of one camplate to the circumference of the other camplate. Both the driving shaft and the driven shaft are resiliently braced so that the tape in every position of the drive is fully applied to said camplates.

United States Patent Westermaier et al.

[151 3,682,006 1 Aug. 8, 1972 [54] MECHANICAL DRIVE [73] Assignee: International Standard Electric Co poration, New York, NY.

22 Filed: 'Sept. 17,1970

21 Appl.No.: 72,952

52 u.s.c1 ..74/s9.2, 74/107 51 Int. Cl. ..Fl6h 9/00 [58] FieldofSearch ..74/l0.6,l0.7,89.2,89.2l,

[56] References Cited UNITED STATES PATENTS 2,061,322 11/1936 Massa, Jr ..74/89.2

Primary Examiner-Milton Kaufman Attorney-C. Cornell Remsen, Jr., Walter J. Baum, Paul W. Hemminger, Charles L. Johnson, J12, Philip M. Bolton, lsidore Togut, Edward Goldberg and Menotti J. Lombardi, Jr.

57 ABSTRACT A mechanical drive is provided for actuating the tuning means in radio equipments for converting a uniform rotary movement into a non-uniform rotary movement with the aid of camplates. The two camplates of almost the same shape and size are arranged paraxially next to each other, the face surfaces thereof almost touch each other, and said camplates are in connection with one another via a tape which, upon actuation of the drive shaft, extends from the circumference of one camplate to the circumference of the other camplate. Both the driving shaft and the driven shaft are resiliently braced so that the tape in every position of the drive is fully applied to said camplates.

2 Claim, 4 Drawing Figures PATENTEDAuc 8 I972 ATTORNEY MECHANICAL DRIVE The present invention relates to a mechanical drive for actuating the tuning means in radio equipments for converting a uniform rotary movement into a nonuniform rotary movement with the aid of camplates.

For converting a uniform rotary movement into a non-uniform rotary movement it is known to use toothed wheels with the radii thereof being dimensioned to follow a given function. The manufacture of such non-circular toothed wheels is very expensive and is only worthwhile in cases where these wheels can be manufactured in large quantities.

In connection with the tuning of radio equipments it is desirable for the frequency values to be distributed as linearly as possible along the dial. This might be enabled, for example, by using non-circular toothed wheels for actuating the tuning means. In this case, however, the radii of the toothed wheels can never be determined in advance with such a high accuracy as to enable an economic manufacture thereof.

For this reason, and for example from the German Pat. No. 701,834, it is already known to use camplates for actuating the tuning means via a lever drive. These drives, however, do no longer satisfy the present-day requirements with respect to the accuracy of fire of the frequency tuning, because the lever drive, owing to the resting friction at the camplate, is incapable of following slight tumings of the drive shaft.

The invention is based on the problem of achieving a high accuracy of tire of the frequency adjustment and the linearization thereof in drives of the type mentioned hereinbefore, without the use of toothed wheels.

The invention is characterized by the fact that two camplates of almost the same shape and size, are arranged paraxially next to each other, that the face sides thereof almost touch one another, that the camplates are in connection with one another via a tape which,

upon actuating the drive shaft, runs from the circumference of one camplate to the circumference of the other camplate, and that both the driving and the driven shaft are resiliently braced in such a way that the tape, in every position of the drive, is fully applied to the camplates.

Such a drive meets the demands as placed thereon and, without requiring any noteworthy investment, permits the adaptation to any arbitrary distribution of the frequency values on the dial.

Examples of embodiment of the inventive type of drive will now be described hereinafter with reference to FIGS. 1 and 2 of the accompanying drawings, in which:

FIG. 1 shows a drive employing a bracing of the camplates by means of a tensioned tape,

FIG. 1a is a bottom view of FIG. 1,

FIG. 2 shows a drive employing a bracing of the camplates by means of anti-backlash or split-type gearwheels, and

FIG. 2a is a bottom view of FIG. 2.

The example of embodiment of the inventive type of drive according to FIG. 1 comprises a drive shaft 1 with a camplate 2 and a driven shaft 3 with a camplate 4 which are supported in a plate 5. The two camplates 2 and 4 are coupled to one another via a tape 6 which may consist of steel, and which is respectively screwed to the ends of camplates. The camplates 2 and 4 are arranged so closely next to each other on the plate 5 that they, in all positions of the drive, are in contact via the tape 6. The shown position applies to the right hand limit stop of the drive shaft 1 in which the shafts l and 3 have the same angle of rotation in relation to the reference lines. When turning the shaft 1 in the left hand direction, the camplate 4, owing to the positive connection by the tape 6, is taken along by the cam plate 2, with the rotational speed of the shaft 3 each time differing by an amount from that of the shaft 1 which is determined by the aspect ratio of the radii of the camplates which are just in contact. When reaching the left hand limit stop of the drive shaft 1, both the shafts l and 3 have performed the same angle of rotation of 180.

In order to prevent the drive from having any backlash, and'in order to safeguard that the tape 6 is always tensioned rollers 7 and 8 are provided on the shafts 1 and 3 on which there is positioned a second tape 9 which is tensioned by a tension spring 10.

Another example of embodiment for bracing the camplates is shown in FIG. 2 in which identical parts are indicated by the same reference numerals as in FIG. 1. According to this example of embodiment a toothedor gear-wheel 12 is firmly arranged on the shaft 1, and a toothed-or gearwheel 13 is rotatably arranged on the shaft 3. The two toothed-or gearwheels l2 and 13 are of equal size and are in engagement with one another.

The toothed-or gearwheel 13 is in connection with the shafi 3 via a spiral spring 14 which is so biased or pre-tensioned that there will be effected a bracing of the camplates 2 and 4 having the same effect as the arrangement according to FIG. 1.

What is claimed is:

l. A mechanical drive for actuating tuning means in radio equipments for converting a uniform rotary movement into a non-uniform rotary movement com prising:

a support plate;

a first cam plate mounted on a first shaft in said plate;

a second cam plate mounted on a second shaft in said support plate, said second shaft mounted on an axis parallel to the axis of said first shaft, said second cam plate having substantially the same shape and size as said first cam plate, and said first and second cam plates are mounted adjacent each other in the same plane;

a tape respectivelyfixed to the ends of said cam plates, such that in all positions of drive of said cam plates, the camming surfaces contact each other through said tape;

means mounted on said first and second shafts and coupling said shafts to resiliently brace said tape in every position of drive;

said means to resiliently brace said tape includes another tape mounted on rollers firmly arranged on said first and second shaft; and

said other tape is tensioned on the rollers by means of a tension spring.

2. A mechanism for converting a uniform rotary movement into a non-uniform rotary movement comprising in combination;

a support means;

a first cam plate mounted on a first shaft in said support means;

a second cam plate mounted on a second shaft in said support means, said second shaft mounted on an axis parallel to the axis of said first shaft, said second cam plate having substantially the same shape and size as said first cam plate, and said first and second cam plates are mounted adjacent each other in the same plane;

tape respectively fixed to the ends of said cam plates, such that in all positions of drive of said cam plates, the camming surfaces contact each 

1. A mechanical drive for actuating tuning means in radio equipments for converting a uniform rotary movement into a nonuniform rotary movement comprising: a support plate; a first cam plate mounted on a first shaft in said plate; a second cam plate mounted on a second shaft in said support plate, said second shaft mounted on an axis parallel to the axis of said first shaft, said second cam plate having substantially the same shape and size as said first cam plate, and said first and second cam plates are mounted adjacent each other in the same plane; a tape respectively fixed to the ends of said cam plates, such that in all positions of drive of said cam plates, the camming surfaces contact each other through said tape; means mounted on said first and second shafts and coupling said shafts to resiliently brace said tape in every position of drive; said means to resiliently brace said tape includes another tape mounted on rollers firmly arranged on said first and second shaft; and said other tape is tensioned on the rollers by means of a tension spring.
 2. A mechanism for converting a uniform rotary movement into a non-uniform rotary movement comprising in combination; a support means; a first cam plate mounted on a first shaft in said support means; a second cam plate mounted on a second shaft in said support means, said second shaft mounted on an axis parallel to the axis of said first shaft, said second cam plate having substantially the same shape and size as said first cam plate, and said first and second cam plates are mounted adjacent each other in the same plane; a tape respectively fixed to the ends of said cam plAtes, such that in all positions of drive of said cam plates, the camming surfaces contact each other through said tape; and means mounted on said first and second shafts and coupling said shafts to resiliently brace said tape in every position of drive including another tape mounted on rollers firmly arranged on said first and second shaft, and said other tape is tensioned on the rollers by means of a tension spring. 